Association of Fecal Indicator Bacteria with Human Viruses and Microbial Source Tracking Markers at Coastal Beaches Impacted by Nonpoint Source Pollution

McQuaig, Shannon M.; Griffith, John F.; Harwood, Valerie J.

doi:10.1128/aem.00024-12

Cited by 113 publications

(88 citation statements)

References 52 publications

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“…However, our previous work had shown that recovery of HPyVs from the DNA extraction protocol was ϳ91% (see the supplemental material for reference 31) and that recovery, including the filtration protocol, was ϳ79% when virus numbers were ϳ10 5 per filter (the cell number recommended by the U.S. EPA for assessing recovery through filtration [50]). …”

Section: Discussionmentioning

confidence: 99%

Performance of Two Quantitative PCR Methods for Microbial Source Tracking of Human Sewage and Implications for Microbial Risk Assessment in Recreational Waters

Staley

Gordon

Schoen

et al. 2012

Appl Environ Microbiol

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139

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Before new, rapid quantitative PCR (qPCR) methods for assessment of recreational water quality and microbial source tracking (MST) can be useful in a regulatory context, an understanding of the ability of the method to detect a DNA target (marker) when the contaminant source has been diluted in environmental waters is needed. This study determined the limits of detection and quantification of the human-associated Bacteroides sp. (HF183) and human polyomavirus (HPyV) qPCR methods for sewage diluted in buffer and in five ambient, Florida water types (estuarine, marine, tannic, lake, and river). HF183 was quantifiable in sewage diluted up to 10 ؊6 in 500-ml ambient-water samples, but HPyVs were not quantifiable in dilutions of >10 ؊4 . Specificity, which was assessed using fecal composites from dogs, birds, and cattle, was 100% for HPyVs and 81% for HF183. Quantitative microbial risk assessment (QMRA) estimated the possible norovirus levels in sewage and the human health risk at various sewage dilutions. When juxtaposed with the MST marker detection limits, the QMRA analysis revealed that HF183 was detectable when the modeled risk of gastrointestinal (GI) illness was at or below the benchmark of 10 illnesses per 1,000 exposures, but the HPyV method was generally not sensitive enough to detect potential health risks at the 0.01 threshold for frequency of illness. The tradeoff between sensitivity and specificity in the MST methods indicates that HF183 data should be interpreted judiciously, preferably in conjunction with a more host-specific marker, and that better methods of concentrating HPyVs from environmental waters are needed if this method is to be useful in a watershed management or monitoring context. Fecal indicator bacteria (FIB), including fecal coliforms, Escherichia coli, and enterococci, have been approved indicators of sewage contamination in recreational waters for decades (49, 51). Swimmers exposed to waters contaminated with sewage are at a greater risk of infection by human pathogens, and subsequent gastrointestinal or other illnesses, than those exposed to unimpacted waters (57). The use of FIB to detect sewage contamination, however, relies on the assumptions that elevated FIB concentrations are representative of pathogen presence and that the fate of these bacteria mimics that of pathogens. Unfortunately, previous studies have shown that concentrations of FIB do not necessarily correlate well with bacterial, protozoan, and viral pathogens (2,20).To address the limitations of FIB, microbial source tracking (MST) methods have been developed to identify human fecal contamination (e.g., sewage) in recreational waters (7, 32). These methods are culture independent and are therefore more rapid than FIB methodologies that require a culture step. The potential for same-day results provides the possibility of advisories that reflect current conditions, rather than day-old ones, which allows more-immediate action to protect against public health risks posed by recreational water use (12, 56). The selecti...

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Section: Discussionmentioning

confidence: 99%

Performance of Two Quantitative PCR Methods for Microbial Source Tracking of Human Sewage and Implications for Microbial Risk Assessment in Recreational Waters

Staley

Gordon

Schoen

et al. 2012

Appl Environ Microbiol

Self Cite

139

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“…The reason for this recommendation is that viral and current bacterial indicators do not correlate and so current bacterial indicator limits do not exclude viral contamination in pathogenic levels. Recent data suggests that the adding of another bacterial indicator correlates with adenoviruses (Sauer et al, 2011) but not always (McQuaig et al, 2012).…”

Section: Virusesmentioning

confidence: 99%

Routine screening of harmful microorganisms in beach sands: Implications to public health

Sabino

Rodrigues

Costa

et al. 2014

Science of The Total Environment

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Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the "Microareias 2012" workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications.

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“…For example, in a study by McQuaig et al, the presence of adenoviruses was correlated with HPyVs and human-associated Bacteroides sp. strain HF183 at Doheny Beach on the west coast of the United States (7). Other studies have shown that human-associ-ated Bacteroides and HPyVs demonstrated persistence similar to that of pathogens such as adenovirus and enterovirus (8).…”

mentioning

confidence: 94%

Alternative Fecal Indicators and Their Empirical Relationships with Enteric Viruses, Salmonella enterica, and Pseudomonas aeruginosa in Surface Waters of a Tropical Urban Catchment

Liang

Goh

Vergara

et al. 2015

Appl Environ Microbiol

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The suitability of traditional microbial indicators (i.e., Escherichia coli and enterococci) has been challenged due to the lack of correlation with pathogens and evidence of possible regrowth in the natural environment. In this study, the relationships between alternative microbial indicators of potential human fecal contamination (Bacteroides thetaiotaomicron, Methanobrevibacter smithii, human polyomaviruses [HPyVs], and F؉ and somatic coliphages) and pathogens (Salmonella spp., Pseudomonas aeruginosa, rotavirus, astrovirus, norovirus GI, norovirus GII, and adenovirus) were compared with those of traditional microbial indicators, as well as environmental parameters (temperature, conductivity, salinity, pH, dissolved oxygen, total organic carbon, total suspended solids, turbidity, total nitrogen, and total phosphorus). Water samples were collected from surface waters of urban catchments in Singapore. Salmonella and P. aeruginosa had significant positive correlations with most of the microbial indicators, especially E. coli and enterococci. Norovirus GII showed moderately strong positive correlations with most of the microbial indicators, except for HPyVs and coliphages. In general, high geometric means and significant correlations between human-specific markers and pathogens suggest the possibility of sewage contamination in some areas. The simultaneous detection of human-specific markers (i.e., B. thetaiotaomicron, M. smithii, and HPyVs) with E. coli and enterococcus supports the likelihood of recent fecal contamination, since the human-specific markers are unable to regrow in natural surface waters. Multiple-linear-regression results further confirm that the inclusion of M. smithii and HPyVs, together with traditional indicators, would better predict the occurrence of pathogens. Further study is needed to determine the applicability of such models to different geographical locations and environmental conditions. Indicator bacteria, such as Escherichia coli and enterococci (ENT), have been used extensively in past decades to indicate the presence of human enteric pathogens because of the great diversity of pathogens, the large volumes required, and the difficulty in concentrating the typically low concentrations of pathogens from water samples. In Singapore, microbial water quality guidelines for recreational freshwater currently target enterococci (less than 200 counts per 100 ml for 95% of the time).Despite the wide use of fecal indicator bacteria in microbial water quality monitoring, their suitability to represent a level of health risk is still being questioned. One of the reasons is the lack of data correlating the presence and concentrations of the indicators with the presence of disease-associated pathogens. With improvements in microbiological test methods and bacterial species identification, there is growing evidence that fecal indicator bacteria, including E. coli and ENT, do not necessarily correlate well with some of the enteric pathogens, particularly viruses (1). There is also evidence that E. ...

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Association of Fecal Indicator Bacteria with Human Viruses and Microbial Source Tracking Markers at Coastal Beaches Impacted by Nonpoint Source Pollution

Cited by 113 publications

References 52 publications

Performance of Two Quantitative PCR Methods for Microbial Source Tracking of Human Sewage and Implications for Microbial Risk Assessment in Recreational Waters

Performance of Two Quantitative PCR Methods for Microbial Source Tracking of Human Sewage and Implications for Microbial Risk Assessment in Recreational Waters

Routine screening of harmful microorganisms in beach sands: Implications to public health

Alternative Fecal Indicators and Their Empirical Relationships with Enteric Viruses, Salmonella enterica, and Pseudomonas aeruginosa in Surface Waters of a Tropical Urban Catchment

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